The invention concerns a mobile crane with an elongated boom.
Longer and longer booms are being required in special applications. The problem of raising very long booms arises particularly in connection with the erecting of wind generators. Booms of this type are usually raised with an extension derrick boom with attached derrick ballast. However, this is very time-consuming, and in the difficult terrain in which wind generators are often located it is very difficult to do.
Theoretically it is already known how to equip main booms with rocking grid tips. In rocking tips of this type, retainer devices must be provided. Furthermore, after the main boom is raised, they are usually in a bent position in relation to the main boom.